<b-button type="primary">显示一个loading提示</b-button>

<script>
  const button = document.querySelector('b-button');

  button.addEventListener('click', () => {
    const messageId = window.BMessage.loading({ content: '正在加载...', duration: 0 });
    setTimeout(() => {
      window.BMessage.closeMessage(messageId);
    }, 5000);
  });
</script>